An estimated 3.2 million kids ages 5 to 12 take mixed-martial arts classes, and some are training to administer beatdowns modeled after the adults’ Ultimate Fighting Championships, according to a January report in ESPN magazine. The magazine profiled the swaggering, mohawked Derek “Crazy” Rayfield, 11, and the meek, doll-clutching fighting machine, Regina “The Black Widow” Awana, 7.